boilers ignition keeps coming on and off while the taps are running have ho?

depends what kind of boiler you have
if it has a preheat function then heating wont come on if you have dripping hot water taps
it might be possible to turn the preheat off so that the heating works
without knowing specific make & model of boiler cant help you further

manwithnoname
June 2012

could be faulty flow /pressure switch or pcb

ji
June 2012